[heoblitz]

Summary

Follows #38. The built panels lived inside the iOS source tree
(SDK/iOS/Sources/<Module>/Panels/<id>), and the Android build reached into that
tree to package them. A panel is platform neutral, so each plugin now has one
folder that holds everything it ships:

SDK/Plugins/<Name>/
  Panel/      the built panel, committed and shared
  iOS/        Swift sources
  Android/    Gradle module

• SDK/iOS and SDK/Android keep the bridge. Plugins without a panel
  (ProcessMetric, URLSessionCapture, OkHttpCapture) move too, so every plugin
  is found in one place.
• Swift targets point at the plugin folder with sources: ["iOS"] and
  resources: [.copy("Panel")]. Panel is the directory NectoPluginPanel looks
  up by default, so the plugins no longer name a subdirectory.
• Gradle modules keep their names and coordinates; settings.gradle.kts only maps
  them to the new directories. NectoPanelResources takes the panel directory
  beside the module instead of searching the iOS tree.
• The panel vite.config.ts files build into SDK/Plugins/<Name>/Panel.
• Product names, module names and Maven coordinates are unchanged.

Test Plan

• swift test for the SDK package and the SDK consumer fixture pass, including
  the check that each selected plugin product provides its panel.
• swift test --package-path NectoMac passes.
• NectoThemeTests, which reads the panel styles from their new location, passes.
• node script/check-panel-assets.mjs passes.
• All twelve Gradle projects configure, and the JVM modules build, generate their
  panel resources and pass their tests.
• JitPack built commit 552213d55f and published all eleven modules.

Not run locally, covered by this PR's CI:

• The Android library modules and the sample, script/test-android-artifacts and
  script/test-android-consumer.
• The web build. Only the output paths changed; the committed panels are the
  existing build output, moved.

Not verified:

• An iOS device or simulator build, and the Android device checks.